Really bad or badly

[tufguy]

"It hurts really bad" or "It hurts really badly". Which one is correct and why?. Some people say bad some say badly. I am totaly confused.

 

[Rover_KE]

They are both correct. 'Bad' here is legitimately used as an adverb meaning 'badly'.

 

[emsr2d2]

I wouldn't use it in an exam situation.

 

[MikeNewYork]

The use of "bad" as an adverb is called a flat adverb. It is colloquial.